Sound-interference device.



J. A. BURGESS & G. B. HUTCHINGS.

SOUND INTERFERENCE DEVICE. APPLICATION FILED Aue.I0. 1917.

Patented Apr. 15,1919.

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J. A. BURGESS & G. B. HUTCHINGS. SOUND INTERFERENCE DEVICE.

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APPLICATION FILED AUG. I0, I91]. Pmvntod Apr. 15,1919.

" UNITED STATES PATENT OFFICE.

JOHN A. BURGESS, or ronon'ro, cnmim, AND enoacn B. nu'rcnmes, or mcnuoiin, I VIRGINIA. v

SOUND-INTERFERENCE DEVICE.

Application filed August 10, 1917. Serial No. 185,578.

; To all whom it ma! concern:

Be it known t at we, JOHN ARMSTRONG Btmonss, a citizen of the Dominion of (Janada, residing at Toronto, Canada, and Gnonon B. HU'ronINos, a citizen of the United States, residing at Richmond Virginia, have invented new and useful Improvements in Sound-Interference Devices, of which the following is a specification.

This invention relates to'means for selecting out a particular sound from a composite sound such as in the detection and location of a marine vessel by picking out its charac teristic' sound from amon all those others in the sea. The ob'ect o the invention'is for such marine wor but it has many other uses.

The invention consists primarily in the selectionof sound by interference and the construction and arrangement of the interference devices; secondarily, the combining of a refining arrangement of resonators and an interference device; and thirdly, a refining arrangement of either interference devices or the combination of resonators and interference devices.

The invention is illustrated in the accompanying'drawings in which Figure 1 shows diagrammatically a comlete combination system of resonators and Interference devices. The various devices are shown some in sectional views and others in elevation with the section of the interference devices taken in the vertical, longitudinal plane passing through the necks 25 and 27.

Fig. 2 is a perspective view of one of our banks of interference devices.

Fig. 3 shows a modified form of inter-- ference device.

Fig. 4 is a cross sectional view through the vertical center of the bank of devices shown in Fig. 1.

- Fig. 5 shows means for adjusting the resonating devices.

Fig. 6 shows a modified form of resonator.

In the drawings, the numeral -11 represents a plurality, preferably, but not neces sarily three, resonators arranged as illustrated at approximately right angles to'each other with the entrance of one adjacent the exit of another. These devices are arranged in any casing such as a cover of wax or paraffin wherein the relative position of the devices to each other may be slightly ad- Specification of Letters Patent.

Patented Apr. 15, 1919.

justed. A megaphone 13 is adapted to direct 'sound into the mouth of the top reso iator and an electrical sound receiver 14 having a sounding board 15, directs sound into the megaphone 13. The receiver 14 is electrically connected by means of a circuit inclosed in a conduit to a microphone 164.0 which selected sound is directed by a resonator 17 carried in a housing 18 insulated against sound, also carrying the microphone 16. This housing may be submerged or not depending upon requirements. The exit of the lower resonator 11 is connected-by tubing 19 to a'bank of interference devices.

This bank of devices is formed of a plurality of endless tubes 20, 21, 22, 23, 24, superposed for convenience, connected together on alternate sides (see Fig. 4) by necks 25, 26, 27, and 28. The tubes are formed to have'telescopic sections 29, 30, 31, 32, and 33 respectively each provided with an operating handle34, 35, 36, 37, and 38. For future reference, the receiver, megaphone, resonator set and bank above described will be designated collectively by the letter A. The lower neck 39 of the bank of interference devices has connected thereto an ear piece 40.

Assuming now that what has been described so far constitutes a complete system, from the composite sound reaching the easing 18, the resonator 17 selects out the desired sound but the resonated sound has impurities in it so the purpose of the other devices is to refine or purify it. From the resonator 17 it is conducted to any suitable place, where the refining apparatus can be conveniently set up, by means of the microphone 16 and its electrical connections'and is reproduced by means of the receiver, sound board and megaphone 14, 15, and 13. Here it is passed through the three resonators where its refinement begins by freeing it of its most prominent reverberations and emphasizing the desired sound, and then it is conveyed by tube 19 to the bank of interference devices where it is purified of all sounds having different wave lengths from the one desired except possibly its immediate over and undertone. This is done by causing the undesirable sounds to interfere with each other as they meet after passing around the endless tubes both ways from the inlet neck. They meet at the outlet neck and interfere and silence themselves due to the fact that the distance around the tube to the left from the plane of the inlet ,an'd'outlet to the tube is one-half wave length or multiples of one-half wave length less than around the other way. This proportion is producedby moving the telescopic portion conslstmg in first augmenting the desired sound above the undesired ones by meansof of the tube in or out by its handle. Whena tube is set to deaden sound of a particular wave length, all others (and the desired one) pass through unaffected. A tube 'is provided for each undesired sound that gets through the resonators 11 which we find rarely exceeds five. When the bank is set to blot out all the undesired sounds it is found that the telescopic portions usually extend from the tubes in harmonic ratios.

The telescopic portions are set by experi- *menting or by calculation, but we find one rapidly becomes proficlent in foretelling the proper position of the telescopic portions by comparison with the first one set by experiment. From the bank the substantially pure desired sound issues and can be heard by the operator through the ear piece 40.

If, however, the sound is not as pure as is required, it can be further refined and purified by passing it to a microphone 41, stepping it up by an audion 42 and then through one or more devices A each consisting of megaphone, resonators and interference bank as above described so that when heard by the operator through ear piece 43 it is an absolutel pure sound.

Instead 0 an interference bank of endless tube units, we find the units can be of cylindrical form as shown at 44 in Fig. 3 or a curved end 45 may be provided or these forms may be combined, so long as telescopic portions 46 and 47 are provided.

.Under varying weather and sound conditions, it is necessary to adjust the elements 11, 13, 14 and 15 so to this end Fig. 5 shows representative means for permitting universal adjustment of these elements relative to eachother. As any adjusting means is contemplated it does not seem necessary to describe anyone in detail.

Fig. 6 shows a modified' form of resonator I which is adjustable to select one of a ran e of sounds and comprises a cylindrical b0 y 48 having aplunger 49 movable therein provided with a duct 50 therethrough for conveying the resonated sound through the stem 51 to a conducting tube 52. 53 represents a handle for operating the plunger.

What we claim is: 1. A method of purifying composite sound consisting in eliminating or counterbalancing each undesired sound by causing it to interfere with -itself.

2. A method of purifying composite sound resonators and then eliminating each undesired sound by causing it to interfere with itself.

3. In combination, a group of resonators for selecting out from a composite sound a limited range of sounds and augmenting therefrom the desired sound above the others, a group .of connected interference devices of different lengths adapted to silence each undesired or unaugmentedsound received from the group of resonators, and means for conveying the selected sounds from the resonators to the interference devices.

4. The device of claim .3 in which the length of the interference devices is adjustable.

5. A device for use in sound purification comprising a group of connected interference tubes of different lengths into which a plurality of sounds is adapted to pass of which one sound is adapted to interfere with itself in each tube of the group whereby it is silenced.

6. The device of claim 5 in which the length of the tubes is adjustable.

7. The device of claim 5 in which the tubes of the group have connecting necks therebetween at substantially right angles to the tubes. 7

8. The device of claim 5 in which the tubes have staggered connecting necks therebetween.

9. A device for use in sound purification comprising a group of interference tubes of different lengths connected together by ..-,each tube comprising av U-shaped d a 'U-shaped telescopic slide fitting e legs of the U-shaped tube.

1 O.'.A--sound treating device comprising a connected group of tubes into which a plurality-of sounds is adapted to pass of which one sound for each tube of the group is adapted to be changed in phase in passing through the group.

JOHN A. BURGESS. GEORGE B. HUTCHINGS. 

